Migrating off then becomes a huge task when you have near zero platform diversity.
You are exposed to all the ancient problems associated with vendor lock in and single points of failure.
Maybe I've missed something, but at this scale wouldn't you want abstracted platform diversity?
i find it amusing when developers are dismissive of older vendors are architectures, and then they end up with a single cloud, utilizing all sorts of proprietary services.
they think they are doing something very different. but the old boss is the new boss and the large public clouds enjoy insane levels of lock in, leverage, and profit margins.
Google's marketing is very strong to easily manipulated decision makers. During the pitch they throw everything at them. Offer incentives (free tablet or Chromebook for every employee, heavily subsidized gsuite migration) and promise infinity.
I feel decision makers, reading industry "reports" from the consultancy megacorps are told the tides a changing, and to keep their job prospects open, adopt a major migration project.
I've never seen one of these leaders remain in position even half way through the clusterf&+k they started. Not one